1. Field of the Invention
The present invention relates to a method for the automatic, correctly positioned transfer and clamping of workpieces, especially rotationally-symmetrical, thin-walled workpieces, which are imparted on interdependent finishing or processing on both sides thereof in a machining work station, in which the workpiece is retained through the intermediary of vacuum-operated clamping units, and which are maintained in a transferring and receiving work station through main spindles coaxially facing towards each other. Furthermore, the invention relates to an arrangement for implementing the above-mentioned inventive method for the automatic, correctly positioned transfer and clamping of workpieces, especially, rotationally-symmetrical, thin-walled workpieces.
The implementing of the automatic finishing or machining on both sides of especially thin-walled, rotationally-symmetrical parts requires an automatic handling of such parts which will ensure the correctly positioned transfer of the parts from one work station to a subsequent work station. The importance of the precision of the transfer of the parts substantially precludes the utilization of handling or manipulating apparatuses. The parts, in effect, the workpieces, must be transferred directly from one work station having a main spindle and a clamping collet, to another work station, in order to eliminate the sources of error caused by handling apparatuses which are arranged between the workpieces. The utilization of vacuum-operating clamping devices is a prerequisite to the finishing and profiling of both sides of the workpieces.
2. Discussion of the Prior Art
A method for the clamping of workpieces, as well as an arrangement for implementing this method with the aid of vacuum-operated clamping units, is known, for example, from the disclosure of German Laid-Open Patent Application No. 31 26 720. Pursuant to this method, an air cushion is generated at discretely located support points on the workpiece with the aid of the clamping units, on which a workpiece can be floatingly slid into the applicable work position, so as to be finally clamped fast through the application of a vacuum. This method and the respective arrangement can, however, only be employed when the workpieces essentially are large-sized and flat, have a thin wall thickness, and are positioned on a plurality of support points. A correctly positioned transfer of the workpieces cannot be attained with this arrangement.